The invention relates to the new compound 3-(3-iodopropargyloxy)-propionitrile, a process for its preparation and its use in microbicidal agents.
Di- and triethylene glycol alkyl/aryl 3-iodo-2-propinyl ethers and substituted 1-(3-iodo-2-propinyloxy-)-2- and -3-propanols which are used as antimicrobial agents are known from DE-OS (German Published Specification) No. 3,224,503 and DE-OS (German Published Specification) No. 3,304,899.
Although the compounds described in the German Offenlegungsschriften (German Published Specifications) in general have a high microbicidal activity, their production and use in preservatives is severely impaired by their physical properties. In particular, the compounds are in general not crystalline, but are oils. Purification of the compounds is thereby made difficult. Purification is, however, in all cases essential to remove discolorations and impurities caused by the production, since colored active compounds cannot be used for the preservation of colourless products. Moreover, from the toxicological viewpoint, it is desirable for the compounds employed to be free from impurities.
Purification by distillation, which is otherwise customary for liquids, cannot be carried out on an industrial scale on the iodopropargyl compounds such as are described in the German Offenlegungsschriften (German Published Specifications) mentioned, because these compounds are unstable to heat and can thereby decompose even explosively (compare H. G. Viehe, Chemistry of Acetylenes, New York 1969, page 691).